Limiting A Suspension Fork's Travel

Discussion in 'Bicycle Repair' started by 5-7HEAVEN, May 4, 2011.

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  1. 5-7HEAVEN

    5-7HEAVEN Guest

    Is there any way of limiting a 100 mm suspension fork to about 25 mm?

    I installed a 29er ROCKSHOX Dart 3 suspension fork on my 26" Diamondback frame. Everything fits well, except that I have my engine mounted ala Scooterguy. The Tanaka three-piece pipe I use runs over the top tube, then crosses under the down tube between the frame and the 29" tire. There is about 1" clearance there, before the suspension fork compresses and the pipe mashes against the Schwalbe Big Apple tire.

    This ROCKSHOX fork has a lockout feature. When locked out, this fork becomes solid and unsuspended. I could use this feature and rely on the 29" tire's rebound. As a last resort, I COULD run a 26" tire with the 29er fork.

    If I can limit the suspension fork's travel to 1", that much and the rebounding feature of the 29" fat tire should be enough for street use.

    Has anyone limited their suspension fork's travel? I imagine I could install clamps on both tubes, but the metal clamps might distort the tube it clamps on. Then, when I remove the clamps, this new ROCKSHOX might ruin the top seals or not work at all. I COULD use rubber tubing and metal sleeves which clamp higher than 100 mm up the tube. That way, if the clamps distort or damage the suspension tubes, they won't destroy the fork's top seals.


  2. loquin

    loquin Active Member

    Maybe some sort of rubber bumper...
  3. 5-7HEAVEN

    5-7HEAVEN Guest

    Thanks for the tip. I'll look for a pair.
  4. wheelbender6

    wheelbender6 Well-Known Member

    WIne corks. The synthetic ones are very durable. I use one in my springer saddle. Smell good too.
  5. 5-7HEAVEN

    5-7HEAVEN Guest

    The fork's tubes are 1.125" diameter by 4.5" tall. I'm looking for tough metal spacers with hard rubber for soft contact with the fork's seals.

    In fact, a stack of metal washers 3.5" high on each tube MIGHT work.:idea:

    However, I'd much rather have a limiter where I don't have to remove and reinstall the fork tubes.
  6. 5-7HEAVEN

    5-7HEAVEN Guest

    The Cheapest Fix.

    I reinstalled my 26" wheel onto the 29" fork. This gives more than adequate clearance to run this new ROCKSHOX Dart 3 fork.

    It may take some time to figure out the best way to limit the 29er fork. Until then, I'll use the 26" wheel.

    Looking forward to the solution. I liked the 29er wheel and Big Apple tire on my bike. It'll soak up the potholes and road cracks.:detective:
  7. loquin

    loquin Active Member

    Spira Footware uses a wavespring in the heel and two at the front of the foot, to cushion your weight as you walk, and to return some of the energy as you walk. These springs are made of thin, flat steel, so that the ones in the heel start off at about 3/8 of an inch high, and compress down to 1/8 of an inch, more or less. (They include a sample spring with some of their shoes, that's kind of neat to play with... And, I was fiddling with it, when I thought about this thread...)

    This flat, wavy spring arrangement allows the combination of a high spring constant, AND a very short, compact spring.

    The ones Spira use are slightly less than 1 inch (I measured .987 inches) ID, and a bit more than 1.25 inches OD. So, while the concept is great for your application, you would need to get a slightly larger ID spring than what Spira uses in their shoes. There are quite a few folks making these springs. The Smiley steel ring company is one. Lee springs is another.

    Unfortunately, it's hard to find a source for pre-made wave springs - typically, they're not 'off the shelf' items. Lee (link above) carries some, and has an online catalog where you can order, but it appears that their minimum order for springs that might fit your application is 10, at $9.60 each... :(

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    Last edited: May 16, 2011